TC2000

TC2000 TRIPATH | Alldatasheet

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Tripath Technology, Inc. - Technical Information 1 TC2000 – KLI/1.1/12-03 TC2000 STEREO CLASS-T™ AUDIO CONTROLLER USING DIGITAL POWER PROCESSING (DPP™) TECHNOLOGY Technical Information Revision 1.1 – December 2003 GENERAL DESCRIPTION The TC2000 is a two channel audio controller that uses Tripath’s proprietary Digital Power Processing (DPPTM) technology. When combined with switching power output stages, the TC2000 allows the implementation of a complete Class-T audio amplifier. Class-T amplifiers offer both the audio fidelity of Class-AB and the power efficiency of Class-D amplifiers.

APPLICATIONS

¾ 5.1-Channel DVD ¾ Mini/Micro Component Systems ¾ Home Theater ¾ Stereo applications BENEFITS ¾ High fidelity, high efficiency Class-T ¾ Analog inputs

FEATURES

¾ Class-T Architecture ¾ Audiophile Quality Sound ¾ 0.007% THD+N @ 30W 8Ω (with TP2050) ¾ High Efficiency ¾ 92% @ 60W 8Ω (with TP2050) ¾ Dynamic Range >100 dB

Tripath Technology, Inc. - Technical Information 2 TC2000 – KLI/1.1/12-03 ABSOLUTE MAXIMUM RATINGS (Note 1) SYMBOL PARAMETER Value UNITS V5 5V Power Supply 6 V Vlogic Input Logic Level V 5+0.3V V TA Operating Free-air Temperature Range -40 to 85 °C TSTORE Storage Temperature Range -55 to 150 °C TJMAX Maximum Junction Temperature 150 °C ESDHB ESD Susceptibility – Human Body Model (Note 2), all pins 2000 V Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. See the table below for Operating Conditions. Note 2: Human body model, 100pF discharged through a 1.5KΩ resistor. OPERATING CONDITIONS SYMBOL PARAMETER MIN. TYP. MAX. UNITS V5 Supply Voltage 4.5 5 5.5 V VHI Logic Input High V5-1.0 V VLO Logic Input Low 1 V TA Operating Temperature Range -40 25 85 °C THERMAL CHARACTERISTICS TC2000 SYMBOL PARAMETER Value UNITS θJA Junction-to-ambient Thermal Resistance (still air) 80 °C/W

ELECTRICAL CHARACTERISTICS

SYMBOL PARAMETER MIN. TYP. MAX. UNITS I5 Supply Current 60 mA fsw Switching Frequency (adjustable via CFB) 600 650 kHz VIN Input Sensitivity 0 1.5 V VOUTHI High Output Voltage V5-0.5 V VOUTLO Low Output Voltage 100 mV RIN Input Impedance 2 kΩ Input DC Bias 2.5 V

Tripath Technology, Inc. - Technical Information 3 TC2000 – KLI/1.1/12-03 TC2000 AUDIO SIGNAL PROCESSOR PIN DESCRIPTIONS Pin Function Description 1 BIASCAP Bandgap reference times two (typically 2.5VDC). Used to set the common mode voltage for the input op amps. This pin is not capable of driving external circuitry. 2, 6 FDBKP2, FDBKP1 Positive switching feedback. 3 DCMP Internal mode selection. This pin must be grounded for proper device operation. 4, 7 FDBKN2, FDBKN1 Negative switching feedback. 5 VPWR Test pin. Must be left floating. 8 HMUTE Logic output. A logic high indicates both amplifiers are muted, due to the mute pin state, or a “fault”. 9, 12 Y1, Y2 Non-inverted switching modulator outputs. 10, 11 Y1B, Y2B Inverted switching modulator outputs.

13 NC No connect

14,16 OCD2, OCD1 Over Current Detect. Ground if not used. 15 REF Internal reference voltage; approximately 1.2 VDC. 17 VNNSENSE Negative power stage over/under supply voltage sense resistor tie point. 18 OVRLDB A logic low output indicates the input signal has overloaded the amplifier. 19 VPPSENSE Positive power stage over/under s upply voltage sense resistor tie point.

20 AGND Ground

21 V5 5 Volt power supply input. 22, 27 OAOUT1, OAOUT2 Input stage output pins. 23, 28 INV1, INV2 Single-ended inputs. Inputs are a “virtual” ground of an inverting opamp with approximately 2.4VDC bias.

24 MUTE

When set to logic high, both amplifiers are muted and in idle mode. When low (grounded), both amplifiers are fully operational. If left floating, the device stays in the mute mode. Ground if not used. 25, 26 BBM1, BBM0 Break-before-make timing control. TC2000 AUDIO SIGNAL PROCESSOR PINOUT BIASCAP FDBKP2 DCMP FDBKN2 VPWR FDBKP1 FDBKN1 HMUTE Y1B Y2B NC OCD2 14 15 REF OCD1 VNNSENSE OVRLDB VPPSENSE AGND OAOUT1 INV1 MUTE BBM1 BBM0 OAOUT2 INV2

Tripath Technology, Inc. - Technical Information 4 TC2000 – KLI/1.1/12-03 APPLICATION / TEST DIAGRAM Inputs and TC2000 ROFA 500K COF .1u;50V RFBC RFBB RI 20K .1u;50V ROFA 500K RFBB OUT1A CFB IN2 TC2000 IN1 ROFA 500K ROFA 500K CFB ROFB CI 2.2u;10V RFBC RF 20K CI 2.2u;10V CFB COF .1u;50V RF 20K OUT2A CS .1u;50V RFBB RI 20K ROFB RFBC J10 RCA RREF 8.2K CFB OUT1B JP JUMPER 1 2 RCA CS 100u;16V RFBB OUT2B Y1B HMUTE Y2B RFBC REF OCD0 VNNSENSE OVRLDB VPPSENSE AGND OAOUT1 INV1 MUTE BBM2 BBM1 OAOUT2 INV2 BIASCAP FDBKP2 DCMP FDBKN2 VPWR FDBKP1 FDBKN1 HMUTE Y1B Y2B NC OCD1 RVNNSENSE 10k RVPPSENSE 20k

Tripath Technology, Inc. - Technical Information 5 TC2000 – KLI/1.1/12-03 EXTERNAL COMPONENTS DESCRIPTION (Refer to the Application/Test Circuit) Component Description RI Inverting input resistance to provide AC gain in conjunction with R F. This input is biased at the BIASCAP voltage (approximately 2.5VDC). RF Feedback resistor to set AC gain in conjunction with R I. Please refer to the Amplifier Gain paragraph, in the Application Information section. CI AC input coupling capacitor, which, in conjunction with RI, forms a high pass filter at )CR2(1f IIC π= . RFBB Feedback divider resistor connected to AGND. The value of this resistor depends on the supply voltage setting and helps set gain in conjunction with RI, RF, RFBB, and RFBC. Please see the Modulator Feedback Design paragraphs in the Application Information Section. RFBC Feedback resistor connected from ei ther the OUT1A/OUT2A to FDBKP1/FDBKP2 or OUT1B/OUT2B to FDBKN1/FDBKN2. The value of this resistor depends on the supply voltage setting and helps set gain in conjunction with RI, RF, RFBB, and RFBC. It should be noted that the resistor from OUT1/OUT2 to FBKOUT1/FBKOUT2 must have a power rating of greater than )(2RVPPP FBC2 DISS = . Please see the Modulator Feedback Design paragraphs in the Application Information Section. CFB Feedback delay capacitor that both lowe rs the idle switching frequency and filters very high frequency noise from the feedback signal, which improves amplifier performance. The value of CFB should be offset between channel 1 and channel 2 so that the idle switching difference is greater than 40kHz. Please refer to the Application / Test Circuit. ROFB Potentiometer used to manually tr im the DC offset on the speaker output. ROFA Resistor that limits the manual DC offs et trim range and allows for more precise adjustment. RREF Bias resistor. Locate close to pin 15 and ground at pin 20. CS Supply decoupling for the power supply pins. For optimum performance, these components should be located close to the TC2000 and returned to their respective ground as shown in the Application/Test Circuit. RVNNSENSE Resistor used to terminate the VNNSENSE pin to AGND. RVPPSENSE Resistor used to terminate the VPPSENSE pin to 5V.

APPLICATION INFORMATION

TK2050 Basic Amplifier Operation The TC2000 is a 5V CMOS signal processor that amplifies the audio input signal and converts the audio signal to a switching pattern. This switching pattern is spread spectrum with a typical idle switching frequency of about 650kHz externally set by the CFB. The switching patterns for the two channels are not synchronized and the idle switchi ng frequencies should differ by at least 40kHz to avoid increasing the audio band noise floor. The idle frequency difference can be accomplished by offsetting the value of CFB for each channel. Typi cal values of CFB with the TP2050 are 470pF for channel 1 and 390pF for channel 2. Complementary copies of the switching pattern are output through the Y1 and Y1B pins and the Y2 and Y2B pins. These signals are used to drive the i nputs of a MOSFET driver. In the generation of the patterns for the MOSFET driver the TC2000 inserts a “break-before-make” dead time between the

Tripath Technology, Inc. - Technical Information 6 TC2000 – KLI/1.1/12-03 turn-off of one transistor and the turn-on of the other in order to minimize shoot-through currents. For applications using the TP2050 please tie BBM0 and BBM1 to 5V for optimal operation. Input Stage Design The TC2000 input stage is configured as an inverting amplifier, allowing the system designer flexibility in setting the input stage gain and frequency response. Figure 1 shows a typical application where the input stage is a constant gain inverting amplifier. The input stage gain should be set so that the maximum input signal level will drive the input stage output to 4Vpp. TC2000 INPUT2 OAOUT2 OAOUT1 CI INV1INPUT1 BIASCAP AGND RF RICI RF AGND INV2 RI Figure 1: Input Stage The gain of the input stage, above the low frequency high pass filter point, is that of a simple inverting amplifier: It should be noted that the input amplifie rs are biased at approximately 2.5VDC. Thus, the polarity of C I must be followed as shown in Figure 1 for a standard ground referenced input signal I F STAGE INPUTV R RA −= Input Capacitor Selection CI can be calculated once a value for R I has been determined. C I and R I determine the input low frequency pole. Typically this pole is set below 10Hz. CI is calculated according to: IP I Rf2 1C π= where: IR = Input resistor value in ohms. Pf = Input low frequency pole (typically 10Hz or below) Modulator Feedback Design The modulator converts the signal from the i nput stage to the high-voltage output signal. The optimum gain of the modulator is determined from the maximum allowable feedback level for the modulator and maximum supply voltage for the power stage. Depending on the maximum supply voltage, the feedback ratio will need to be adjusted to maximize performance. The values of RFBB and RFBC (see explanation below) defi ne the gain of the modulator. On ce these values are chosen, based on the maximum supply voltage, the gain of the modulator will be fixed even as the supply voltage fluctuates due to current draw.

Tripath Technology, Inc. - Technical Information 7 TC2000 – KLI/1.1/12-03 For the best signal-to-noise ratio and lowest distor tion, the maximum differential modulator feedback voltage should be approximately 4Vpp. This will keep the gain of the modulator as low as possible and still allow headroom so that the feedback signal does not clip the modulator feedback stage. The modulator feedback resistors are: RFBB = User specified; typically1kΩ FBB FBBCC FBC R2V RVR −  ∗= Mute Control When a logic high signal is supplied to MUTE, both amplifier channels are muted (both high- and low- side transistors are turned off). When a logic level low is supplied to MUTE, both amplifiers are fully operational. Output Voltage Offset The TC2000 does not have internal compensation for DC offset. If offset is a consideration for the intended application, trimming of the input offset voltage will be required. Tripath has had success with both active and passive circuits for this purpos e; please consult with the Tripath Applications team for further information. HMUTE The HMUTE pin is a 5V logic output that indicates various fault conditions within the device. OVRLDB The OVRLDB pin is a 5V logic output that is asserted just at the onset of clipping. When low, it indicates that the level of the input signal has overloaded the amplifier resulting in increased distortion at the output. The OVRLDB signal can be used to cont rol a distortion indicator light or LED through a simple buffer circuit, as the OVRLDB cannot drive an LED directly. There is a 20K resistor on chip in series with the OVRLDB output.

Tripath Technology, Inc. - Technical Information 8 TC2000 – KLI/1.1/12-03 PACKAGE INFORMATION – TC2000

Tripath Technology, Inc. - Technical Information 9 TC2000 – KLI/1.1/12-03 Tripath and Digital Power Processing are trademarks of Tripath Technology Inc. Other trademarks referenced in this document are owned by their respective companies. Tripath Technology Inc. reserves the right to make changes without further notice to any products herein to improve reliability, function or design. Tripath does not assume any liability arising out of the application or use of any product or circuit descri bed herein; neither does it convey any license under its patent rights, nor the rights of others. TRIPATH’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN CONSENT OF THE PRESIDENT OF TRIPATH TECHNOLOGY INC. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in this labeling, can be reasonably expected to result in significant injury to the user. 2. A critical component is any co mponent of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. For more information on Tripath products, visit our web site at: www.tripath.com Contact Information TRIPATH TECHNOLOGY, INC

2560 Orchard Parkway, San Jose, CA 95131

408.750.3000 - P 408.750.3001 - F For more Sales Information, please visit us @ www.tripath.com/cont_s.htm For more Technical Information, please visit us @ www.tripath.com/data.htm